1) Line an 20-by-20 cm pan with aluminium foil. Set aside.
2) In a large saucepan over medium heat, combine the marshmallow cream, sugar, evaporated milk, butter and salt. Bring to a full boil and cook for 5 minutes, stirring constantly until thick.
3) Remove from heat and pour in the milk chocolate chips. Stir until chocolate is melted and mixture is smooth. Stir in nuts and vanilla. Pour into prepared pan. Chill in refrigerator for 2 hours or until firm.